1. Field of the Invention
The present invention relates to method and apparatus for data processing and more particularly to method and apparatus for connecting intelligent terminals to each other or to a partitioned storage system through a central switch to form a local area network.
2. Description of the Prior Art
In the prior art there many local area network switching systems. The following are systems representative of the prior art.
U.S. Pat. No. 4,379,950, shows a telecommunications switching system using distributed group or modular architecture and time division principals in which data is transmitted on a plurality of buses between processors accessing those buses and in which all data transmitted between processors is stored in a temporary memory within a group or module and is read in response to a scan of that temporary memory. Although the patent shows the computer controlled distributed communications system, it does not teach nor suggest a plurality of intelligent terminals connected to each other and through a central switch to a partitioned memory in accordance with the present invention.
U.S. Pat. No. 3,984,819 shows an interconnection switching matrix for a data processing system including processor units and resource units. The system permits predetermined units to communicate with each other to the exclusion of other units or all units may simultaneously communicate with each other. The patent does not show a system for connecting a plurality of intelligent terminals to each other and through a central switch to a partioned memory in accordance with the present invention.
U.S. Pat. No. 3,648,249 shows an audio responsive visual display system incorporating audio and digital information segmentation and coordination. Terminals are switched under control of a central switch to one of a plurality of operator transcription stations. Although the patent shows a system including a central switch, it does not show a system for connecting a plurality of intelligent terminals to each other and through a central switch to a partitioned memory in accordance with the present invention.
U.S. Pat. No. 3,699,532 describes a partitioned storage system in a multi-programmed data processing system. However, the patent does not show a system for connecting a plurality of intelligent terminals to each other and through a central switch to a partition memory in accordance with the present invention.
U.S. Pat. No. 4,227,178 shows a decentralized data transmission system including a number of terminals connected through transmission stations to a loop. However, the patent does not show a system for connecting a plurality of intelligent terminals to each other and through a central switch to a partitioned memory in accordance to the present invention.
U.S. Pat. No. 4,019,176 shows a system and method for reliable communica-tion of stored messages among stations over a single common channel with a minimization of service message time. Although the stations are interconnected by a single common transmission channel, no central control unit is employed in the system.
U.S. Pat. No. 4,376,982 shows a communication system including a number of requesting units and a number of responding units representing resources. The patent shows interface logic for requestors and resources to create and respond to signals comprising a protocol that consists of a request message broadcast from one requestor to all resources in the network with the capability of providing a desired service; exceptance message transmitted from all resources that receive the request message and can currently provide service; a confirmation message from the requestor to the resource; cancellation messages from the requestor to all other resources; retransmission of acceptance messages by resource until a confirmation or cancellation is received. The patent does not show a system for interconnecting a plurality of intelligent terminals to each other and through a central switch to a partitioned memory in accordance with the present invention.
U.S. Pat. No. 4,323,967 shows a data processing system having a central subsystem including a plurality of special purpose processing units with one of the processing units serving as a control processing unit within the subsystem, processing units being coupled to a common bus for the transfer of data control information and address information within the subsystem. The patent does not show a system for connecting a plurality of intelli-gent terminals to each other and through a central switch to a partitioned memory in accordance with the present invention.
U.S. Pat. No. 4,057,849 shows a text editing and display system including a display controller, a central processor, a memory unit, a plurality of CRT raster scan displays and an input device such as a keyboard. Information from the CPU is passed through a multiplexed memory to display controller's switch write the CRT display with appropriate text information. The terminals do not include any processing capability nor any local storage. The patent does not show a system for connecting a plurality of intelligent terminals to each other and through a shared central switch to a partitioned memory in accordance with the present invention.
U.S. Pat. No. 3,573,747 shows a communication system having a plurality of dumb terminals connected to a central processor wherein all communications must be passed through the central processor from terminal to terminal. The patent does not show a system for connecting a plurality of intelligent terminals to each other and through a central switch to a partioned memory in accordance with the present invention.
IBM Technical Disclosure Bulletin, Vol. 5, No. 2, July 1962, page 61 and following shows a remote terminal system in which a plurality of remote terminals which lack intelligence are multiplexed through a common switch arrangement to one or more buffer storage units. A buffer address memory in the multiplexer has individual locations associated with each terminal for controlling storage unit assignments. However, the article does not show a system for connecting a plurality of intelligent terminals to each other and through a central switch to a partitioned memory in accordance with the present invention.
The prior art discussed above does not teach nor suggest the present invention as disclosed and claimed herein.